// Copyright (c) 2009-2010, Jeremy Brewer
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

package galaxie500.util;

/**
 * Class for timing code execution
 * 
 * This class is a simple wrapper around System.currentTimeMillis() intended to
 * make writing simple benchmarks easy.
 * 
 * Example Usage:
 * 
 * <pre>
 * Timer timer = new Timer();
 * timer.start();
 * ... Big loop ...
 * timer.stop();
 * double time = timer.getTimeSec();
 * </pre>
 * 
 * @author Jeremy Brewer
 */
public class Timer {
  private long startTime = 0;
  private long elapsedTimeMillis = 0;

  /**
   * Starts a timer.
   */
  public void start() {
    startTime = System.currentTimeMillis();
  }

  /**
   * Stops a timer.
   */
  public void stop() {
    long stopTime = System.currentTimeMillis();
    elapsedTimeMillis += (stopTime - startTime);
  }

  /**
   * Resets the internal counter to 0. If called in between calls to start() and
   * stop(), results of getTimeSec() will reflect the entire time between
   * those two calls.
   */
  public void reset() {
    elapsedTimeMillis = 0;
  }

  /**
   * Returns the elapsed time in seconds.
   * 
   * @return The cumulative time between all calls to start() and stop() in
   *         seconds.
   */
  public double getTimeSec() {
    return ((double) elapsedTimeMillis) / 1000.0;
  }
}
